Casting machines for casting battery plate grids

ABSTRACT

For supplying molten lead to a battery plate grid casting machine, a lead pump, immersed in molten lead in a lead pot, is formed as a readily removable cartridge incorporating all the working parts of the pump, which is simply screwed into a fixed body incorporating the delivery pipe.

United States Patent Inventors Alan John Goodwin;

Norman Shanks, both of Swlnton, England 834,963

June 20, 1969 Nov. 9, 1971 Chloride Overseas Limited Swlnton, England June 21, 1968 Great Britain Appl. No. Filed Patented Asaignee Priority CASTING MACHINES FOR CASTING BATTERY PLATE GRIDS 2 Claims, 1 Drawing Fig.

US. Cl 222/385, 164/312, 18/30 AR Int. Cl. 367d 5/50 Field olSearch 164/312, 314, 316, 317, 318, 335; 266/39; 220/14, 9;

[56] Reierences Cited UNITED STATES PATENTS 2,414,061 1 /1947 Richard 220/9 3.430.685 3/1969 Drugowiisch 164/314 662,980 12/1900 Shepard 222/385 1,653,661 12/1927 Riley 222/385 X 1,708,830 4/1929 Clarke 222/385 Primary xaminerl. Spencer Overhoiser Assistant Examiner- Norman E. Lehrer Attorney-Watson. Cole, Grindle & Watson ABSTRACT: For supplying molten lead to a battery plate grid casting machine, a lead pump, immersed in molten lead in a lead pot, is formed as a readily removable cartridge incorporating all'the working parts of the pump, which is simply screwed into a fixed body incorporating the delivery pipe.

CASTING MACHINES FOR CASTING BATTERY PLATE GRIDS This invention relates to apparatus for supplying molten lead to a casting machine, more particularly a machine for casting battery plate grids.

According to the present invention apparatus for supplying molten lead to a machine for casting battery plate grids includes a lead pump immersed in a lead pot and includes a piston and cylinder for drawing in molten-lead from that surrounding it in the pot, and delivering it through an outlet formed in a body secured to the lead pot, and is characterized in that the pump is connected to the body so as to be readily detachable from it. Thus the pump can be readily removed from the lead pot for maintenance or replacement without the necessity for disconnecting any pipe joints. For example the pump may be arranged to be removable from the lead pot by simply unscrewing the cylinder from the body.

Further features and details of the invention will be apparent from the following description of one specific embodiment which will be given by way of example, with reference to the accompanying drawing which is a sectional elevation of a lead pump mounted in a lead pot for supplying molten lead to a machine for casting battery plates and grids.

The machine may for example be as described in the present applicants pending U.S. Pat. application Ser. No. 834,964, filed June 20, I969.

The lead pot comprises a rectangular tank the wall of which is of sandwich construction comprising an inner tank 1 l and an outer tank 12 formed of metal such as steel with the space between them packed with a high quality thermal insulating material 14 such as fiber glass. It is desirable to avoid metallic contact between the inner and outer tanks and a feature of the arrangement is that the gap between the upper edges of these tanks is sealed by a woven asbestos strip 15 which not only takes up any distortion due to different degrees of expansion between the inner and outer tanks, while minimizing heat losses, but also prevents any possibility of the molten lead reaching the thermal insulation 14 if it should overflow, which would virtually render the tank unfit for further use. Preferably the outer wall of the tank has a flange 16 extending over the inner wall so that the bridging strip 15 of the asbestos cloth forms the upper margin of the inner wall. Thus the exposed flange 16 is relatively cool, thereby reducing the chance of discomfort or injury to workers.

Within the lead pot is a lead pump assembly comprising a body 20 of generally V-shape comprising a pair of limbs 21 and 22 formed integrally with a horizontal flange 23 which rests on the lid of the lead pot and may be secured to it by bolts 24. The limbs 21 and 22 extend down substantially to the bottom of the lead pot through a slot in the lid. The limb 21 serves merely as a mechanical stay while the limb 22 also provides a delivery passage for the molten lead, and communicates at its upper end with a flange 25 for securing to a pipe leading to the casting machine, and at its lower end with a chamber 26 opening upwardly through a seating 27.

Screwed into the body is a removable cartridge 30 incorporating all the working parts of the pump. The cartridge comprises a cylinder 31 having near its lower end a shoulder 32 resting on the seating 27 with a washer 33 interposed to form a seal, and at its upper end a screw-threaded portion 34 cooperating with a correspondingly screw-threaded opening 35 formed in the flange 23. The cylinder has a hexagon head 36 by which it can be screwed into and out of position.

Within the cylinder is a piston 40 of any convenient construction carried by a tubular piston rod 41 having at its upper end a head 42 fitting into a socket 43 carried by a pneumatic ram 44 by which the piston rod, and hence the piston, can be reciprocated up and down. The ram 44 is carried by a gantry 45 removably secured to the flange 23 as by bolts 46.

The lower end of the cylinder is formed as a seating 49 for a poppet valve 50 carried by a rod 51 which extends up through a guide 52 in the lower end of the cylinder, and through the hollow piston rod, and has its upper end secured to a block 53.

A handle 54 having a knob 55 extends horizontally from the block 53 through a slot 56 in the hollow piston rod 41. The

latter is surrounded by a washer 57 which is urged upwards against the handle 54 by a spring 58, the lower end of which bears against a washer 59 resting on a shoulder at the lower end of a counter bore in the upper end of the cylinder 31.

The handle 54 is shown for convenience in the plane of the drawing but in fact projects at right angles to it. The slot 56 is of inverted T to so that, as the piston rod reciprocates up and down, the stem portion of the T-shaped slot can move up and down relatively to the handle without moving the valve up and down to the same extent. Moreover there may be a tendency for lead and oxide deposits to form on the valve seating, and in order to remove these the handle can be manipulated so as to rotate the valve relatively to its seating, the rod of the handle then moving in the head portion of the T-shaped slot.

The gantry 45 carries a microswitch 70 mounted on an adjusting screw 71 which can be turned by a handle 72 to adjust the microswitch up and down. The socket 43 is formed with a cam now 73 to actuate the microswitch at a certain point in the stroke of the piston.

The microswitch is connected to means for energizing the pneumatic ram 44 so that by adjusting the microswitch up and down it is possible to adjust the stroke of the piston and hence the amount of molten lead delivered on each stroke.

In operation the valve is biased towards its closed position by the spring 58 and is' opened by the pressure developed under the piston as it descends.

The cylinder is formed with ports 37 communicating with the space surrounding it to allow lead to flow into the cylinder in response to the suction within it when the piston reaches its uppermost position. Thus the molten lead is pumped in metered quantities to a reservoir above the mold from which it is admitted to the mold under the control of a programmed unit.

in order to have access to the working parts of the pump for maintenance or replacement it is only necessary to shift the gantry 45 to one side and unscrew the cylinder by means of its head 36 and withdraw the complete pump cartridge from the lead pot.

in an alternative construction the lower end of the cylinder is in screw-threaded engagement with the lower part of the body, while its upper end is a clearance fit in it. in a further alternative the body is secured to the bottom of the lead pot, instead of the top, and is in the form of a base supporting the cylinder by its lower end only.

WHAT WE claim as our invention and desire to secure by Letters Patent is:

1. Apparatus for supplying molten lead to a machine for casting battery plate grids including a lead pump assembly immersed in a lead pot, said pump assembly including a body having a substantially horizontal top plate and a pair of interconnected limb members extending downwardly therefrom, one of said limb members having a hollow discharge passage and extending upwardly through said plate, said pump assembly further including a self-contained piston and cylinder unit extending between said plate and the lower end of said one limb member in operative communication therewith, said cylinder having inlet ports in its cylinder wall through which molten lead may be drawn in by means of said piston from that surrounding it in the pot and thereafter deliver it through said discharge passage, said piston and cylinder unit being threadedly secured to said plate and having means extending upwardly from said plate for threadedly disengaging said piston and cylinder unit therefrom whereby said unit may be removed without emptying the molten lead from the pot or disconnecting said discharge passage.

2. Apparatus according to claim 1 wherein said cylinder is threadedly secured to said plate, the upper portion of said cylinder extending upwardly from said plate to permit said cylinder to be threadedly disengaged from said plate.

t t i t i 

1. Apparatus for supplying molten lead to a machine for casting battery plate grids including a lead pump asseMbly immersed in a lead pot, said pump assembly including a body having a substantially horizontal top plate and a pair of interconnected limb members extending downwardly therefrom, one of said limb members having a hollow discharge passage and extending upwardly through said plate, said pump assembly further including a selfcontained piston and cylinder unit extending between said plate and the lower end of said one limb member in operative communication therewith, said cylinder having inlet ports in its cylinder wall through which molten lead may be drawn in by means of said piston from that surrounding it in the pot and thereafter deliver it through said discharge passage, said piston and cylinder unit being threadedly secured to said plate and having means extending upwardly from said plate for threadedly disengaging said piston and cylinder unit therefrom whereby said unit may be removed without emptying the molten lead from the pot or disconnecting said discharge passage.
 2. Apparatus according to claim 1 wherein said cylinder is threadedly secured to said plate, the upper portion of said cylinder extending upwardly from said plate to permit said cylinder to be threadedly disengaged from said plate. 